<!DOCTYPE html>
<html>
<head>
	<title></title>
	<style type="text/css">
	*{margin:0;padding: 0;}
		.class1{
			border:1px solid red;
			height: 150px;
			width: 888px;
			margin:0 auto;
			background-color: #ccff00;
		}
		.class2{
			border:5px white solid;
			float: left;
			margin-left: 10px;
			position: relative;
		}
		img{
			width: 200px;
			display: block;
		}
		.txt{
			display: none;
			text-align: center;
			width: 100%;
			position: absolute;
			background-color: #ccc;
			opacity: 0.7;
			color: #fff;
			bottom: 0;
		}
		.class2:hover .txt{
			display: block;
		}
	</style>
</head>
<body>
<div class="class1">
	<div class="class2">
		<img src="http://img2.imgtn.bdimg.com/it/u=460149924,3984768516&fm=26&gp=0.jpg">
		<div class="txt">这是海牛</div>
	</div>
	<div class="class2">
		<img src="http://img2.imgtn.bdimg.com/it/u=460149924,3984768516&fm=26&gp=0.jpg">
		<div class="txt">这是海牛</div>
	</div>
	<div class="class2">
		<img src="http://img2.imgtn.bdimg.com/it/u=460149924,3984768516&fm=26&gp=0.jpg">
		<div class="txt">这是海牛</div>
	</div>
	<div class="class2">
		<img src="http://img2.imgtn.bdimg.com/it/u=460149924,3984768516&fm=26&gp=0.jpg">
		<div class="txt">这是海牛</div>
	</div>
</div>
</body>
</html>